Preheat your oven to 350°F (175°C) and line a baking tray with parchment paper.

Melt ½ cup of unsalted butter in a medium saucepan over medium heat until golden brown.

In a mixing bowl, combine the browned butter with ¾ cup brown sugar and ½ cup granulated sugar until smooth.

Add 1 cup peanut butter, ½ cup sourdough discard, 1 egg yolk, and 1 teaspoon vanilla extract, mixing until smooth.

Sift in 1.5 cups flour, ½ teaspoon baking powder, ½ teaspoon baking soda, and ¼ teaspoon salt; gently mix until just incorporated.

Fold in ½ cup chopped peanuts and ½ cup peanut butter chips.

Portion the dough using a cookie scoop and roll into balls, placing them 2 inches apart on the baking sheet.

Bake for 11-14 minutes, until the edges are set and lightly golden, with soft centers.

Let cookies cool on the baking sheet for 5 minutes before transferring to a wire rack.